It is conventional for high volume mailers to avail themselves of the high speeds offered by modern electronic digital computers and chain printers, in order to reduce costs and increase their output. A typical prior art installation includes a computer which receives information as to the weight and destination of a package, and is programmed to calculate the required postage. A high speed computer output printer is slaved to the computer to print out the destination information on an address label which is subsequently affixed to the package.
The computer also provides the calculated postage amount information to shipping department employees in some form which enables them to affix the proper amount of postage to the package. The most common way of accomplishing this is for the high speed printer to receive the postage amount information from the computer, and print it directly on the address label for the information of the employees who subsequently affix postage. This printing is not an actual government-authorized postage impression of the kind provided by a postage meter. The print impression made in a prior art installation as described above includes only the postage amount without any authorized postage validation symbols, and is provided for information only. Thereafter authorized postage of like amount must be affixed by an employee by affixing postage stamps or using a conventional manually controlled mechanical postage meter.
The intervention of a human being, or of a mechanical postage metering device, slows down a high volume mailing operation of the kind described. Therefore it is desirable to have the authorized postage impression printed automatically in response to the computer-generated postage calculation. It is not enough, however, simply to connect the data output lines of the computer to the input of some insecurely housed apparatus capable of printing authorized postage impressions, as suggested by U.S. Pat. No. 3,225,439 of L. G. Simjian. In accordance with applicable postal security regulations, there must be some secure means of accounting which assures postal officials that all the postage used is paid for. Normally a descending register is filled with a pre-paid postage credit balance, the register is decremented by the amount of postage dispensed, and the postage dispenser is locked when the postage balance falls too low. Subsequently the register can be recharged under secured conditions. It is also possible to extend postage credit to the user, keeping track of a debit balance which increases by the amount of the postage used, and billing the user subsequently. Those skilled in the computer arts will readily appreciate that it is possible to program the computer itself to take care of either type of bookkeeping described above. Such a solution is unsatisfactory, however, because digital computers are so easily re-programmed that an unscrupulous individual could thereby accomplish postal fraud.
This invention contemplates, therefore, that the desired computer control of postage printing be achieved in conjunction with some form of secure, fixed-program postal accounting equipment. One approach which is within the contemplation of this invention is to use a mechanical postage meter which comprises a secure housing containing authorized postage printing means, a mechanical descending register for storing the postal credit balance, and mechanical .[.guaranteeing.]. .Iadd.means .Iaddend.for .[.gauranteeing.]. .Iadd.guaranteeing .Iaddend.that all printed postage amounts are decremented from the register, all of which is conventional. The mechanical meter is modified in accordance with this invention, however, to provide it with an electrically actuated meter controller device connected to respond to electrical signals from the computer, and to translate those signals into a mechanical input for controlling all meter functions. (A system using a lever and clutch mechanism in an electrically actuated meter is shown in U.S. Pat. No. 3,692,988).
The latter approach meets all security requirements, but is considered too slow to meet the speed requirements of some high volume mailing operations. When used in conjunction with an electronic digital computer and high speed printer, it may be necessary for the postage printer to produce approximately two or three postage impressions per second, and mechanical postage meters do not appear capable of withstanding such operating rates over a reasonable lifetime.
In order to achieve longer operating lifetimes and/or higher operating speeds, a preferred form of the invention employs fast-acting electrically driven printing means, electrical means for storing the postage balance, and electrical calculating means for changing the postage balance in accordance with the amount of postage printed. The postage printing means is enclosed within a secure housing, and the electronic control circuitry, or at least that portion of it which bears the responsibility for postal security, is enclosed within the same housing or alternatively is in a separate secure housing and connected to the postage printer by means of secure electrical cable and connector devices.
Equipment in accordance with this aspect of the invention can be used for printing various different kinds of numerical indicia under computer control. For example it is adapted for various non-postage applications having similar security problems, e.g. printing paychecks.
It is also within the contemplation of this invention to provide appropriate security measures which make it practical to use a high speed printer directly for postage printing, after appropriate modifications such as replacing standard print characters by special authorized postage symbols.
That approach, however, has a number of disadvantages, one of which relates to the character size limitation of standard high speed printing equipment. It also involves undesirable interference with the electrical interface between the computer and the high speed printer, i.e. breaking into the electrical cable which connects the computer and the high speed printer in order to insert special circuitry for performing postal security functions.
Therefore a preferred form of this invention provides a separate auxiliary printing mechanism which is arranged in one of several ways to print authorized postage impressions upon the address labels that are fed through the high speed printer. The high speed printer and the postage printer are both controlled ultimately by the computer, but they have individual electrical connections thereto, and therefore, only the connection to the postage printer need be designed with postal security problems in mind.